This invention relates to a data secret protecting system and a method which protects important data to be held by a data holding device such as an encoding device and an accounting device.
A conventional data holding device comprises a microswitch which is placed on a cover of a case which receives the conventional data holding device. The microswitch detects opening of the cover of the case.
However, the conventional data holding device has a disadvantage in that the microswitch can not detect opening of the case when a part excepting the cover of the case is opened. Namely, the conventional data holding device has a disadvantage in that the conventional data holding device is incapable of securely protecting an important data secret to be held by the conventional data holding device.
It is therefore an object of this invention to provide a data secret protecting system and a method which are capable of securely protecting an important data secret.
Other objects of this invention will become clear as the description proceeds.
According to a first aspect of this invention, there is provided to a data secret protecting system comprising:
data holding means received in a case for holding important data;
distortion detecting means received in the case for detecting a distortion value of the case to produce a detected distortion value;
distortion comparing means connected to the distortion detecting means for comparing the detected distortion value with a reference distortion value to produce a compared distortion signal when the detected distortion value is greater than the reference distortion value; and
data erasing means connected to the data holding means and to the distortion comparing means for erasing the important data of the data holding means when the data erasing means is supplied with the compared distortion signal.
According to a second aspect of this invention, there is provided to a data secret protecting system comprising:
data holding means received in a case for holding important data;
distortion detecting means received in the case for detecting a distortion value of the case to produce a detected distortion value;
temperature measuring means received in the case for measuring a temperature value of the case to produce a measured temperature value;
distortion correcting means connected to the distortion detecting means and to the temperature measuring means for correcting, in response to the measured temperature value, the detected distortion value to produce a corrected value of the detected distortion value;
distortion comparing means connected to the distortion detecting means for comparing the corrected value of the detected distortion value with a reference distortion value to produce a compared distortion signal when the corrected value of the detected distortion value is greater than the reference distortion value; and
data erasing means connected to the data holding means and to the distortion comparing means for erasing the important data of the data holding means when the data erasing means is supplied with the compared distortion signal.
According to a third aspect of this invention, there is provided to a data secret protecting system comprising:
data holding means received in a case for holding important data;
distortion detecting means received in the case for detecting a distortion value of the case to produce a detected distortion value;
temperature measuring means received in the case for measuring a temperature value of the case to produce a measured temperature value;
reference distortion correcting means connected to the temperature measuring means for correcting, in response to the measured temperature value, a reference distortion value to produce a corrected value of the reference distortion value;
distortion comparing means connected to the distortion detecting means for comparing the detected distortion value with the corrected value of the reference distortion value to produce a compared distortion signal when the detected distortion value is greater than the corrected value of the reference distortion value; and
data erasing means connected to the data holding means and to the distortion comparing means for erasing the important data of the data holding means when the data erasing means is supplied with the compared distortion signal.
According to a fourth aspect of this invention, there is provided to a data secret protecting method comprising:
a step of holding important data in a case;
a step of detecting a distortion value of the case to produce a detected distortion value;
a step of comparing the detected distortion value with a reference distortion value to produce a compared distortion signal when the detected distortion value is greater than the reference distortion value; and
a step of erasing, in response to the compared distortion signal, the important data.
According to a fifth aspect of this invention, there is provided to a data secret protecting method comprising:
a step of holding important data in a case;
a step of detecting a distortion value of the case to produce a detected distortion value;
a step of measuring a temperature value of the case to produce a measured temperature value;
a step of correcting, in response to the measured temperature value, the detected distortion to produce a corrected value of the detected distortion value;
a step of comparing the corrected value of the detected distortion value with a reference distortion value to produce a compared distortion signal when the corrected value of the detected distortion value is greater than the reference distortion value; and
a step of erasing, in response to the compared distortion signal, the important data.
According to a sixth aspect of this invention, there is provided to a data secret protecting method comprising:
a step of holding important data in a case;
a step of detecting a distortion value of the case to produce a detected distortion value;
a step of measuring a temperature value of the case to produce a measured temperature value;
a step of correcting, in response to the measured temperature value, a reference distortion value to produce a corrected value of the reference distortion value;
a step of comparing the detected distortion value with the corrected value of the reference distortion value to produce a compared distortion signal when the detected distortion value is greater than the corrected value of the reference distortion value; and
a step of erasing, in response to the compared distortion signal, the important data.